male contraception

Male contraception is coming, are men ready for it?

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The world of contraception is set to change real soon, with the advent of the male contraceptive pill. This means that before long, the question of who’s taking ‘the pill’ in a relationship will become a matter of sharing responsibility, rather than having it fall almost exclusively on the female partner.

Yes, there will be needles. (but should that bother you?)

Big Think reports that the Man Pill (well, it’s more a sort of injection,) which will be a “non-hormonal alternative to the condom,” should reach markets as early as 2018. The drug is designed to last a number of years per injection, while being non-permanent. What’s more, the non-hormonal aspect should mean good news for those men who worry about the various side effects women have to endure when taking the “regular” pill. On the flip side, though, it will most definitely entail more doctors fondling your junk. As Big Think’s Monica Joshi explains:

Vasalgel is a polymer that is injected under local anesthetic into the man’s sperm-carrying tubes. These are accessible through the scrotum. However, it is not injected in his penis or testicles. It works by blocking sperm and is expected to be reversible through a second injection that dissolves the polymer. While we don’t completely know its length of efficacy and whether or not it’s fully reversible, medical trials are already on their way, beginning in 2016, to test these possibilities.

Did any of the above make you shrink away a bit? Well, consider what women have to go through routinely at the gynaecologist’s office. A quick jab in your nether regions, under local anaesthetic no less, shouldn’t be so bad.

It should be noted that, exciting though this development is, the Man Pill (Guy Injection? We’ll work on it some more.) – doesn’t serve as a complete replacement for other birth control methods. Most especially, don’t expect the condom to disappear from your night-time arsenal just yet. While this new method would effectively lessen the risk of unwanted pregnancies from otherwise unprotected sexual encounters, the drug does nothing to protect the user from STDs.

What was the holdup, anyway?

It occurs to me that this development is kind of late, considering the way female birth control methods have evolved over the years. Has the notion of male contraception received less attention, historically? Maybe we could have arrived here sooner, or maybe modern medicine has only now made it possible for male contraceptives to work in a non-invasive manner. If nothing else, it seems like we’re headed for a major culture change when it comes to who takes care of what in the bedroom, and perhaps more importantly, what comes after.

Female hormone could be key to male contraceptive

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Progesterone-sensing molecule that guides sperm to egg offers fertility solution.


sperm and egg
Sperm are given and extra boost towards the egg by the hormone progesterone.René Pascal/Center of Advanced European Study and Research, Bonn

A sperm’s path to an egg is more a deadly obstacle course than a track sprint. The one ejaculated sperm cell in a million that is lucky enough to reach the fallopian tubes, where eggs await fertilization, must conquer thick, gelatinous layers of mucus and cells surrounding the egg to reach its prize.

Fortunately for the sperm, there is help. Two studies published today in Nature1,2 show how sperm sense progesterone, a female sex hormone, that has been released by cells surrounding the egg. The hormone may guide the sperm towards the egg as well as giving it a final push to get there, the research suggests. The findings could be used to design a new class of contraceptive drug.

“It really is a significant step forward in terms of how we understand what regulates sperm,” says Steven Publicover, a reproductive biologist at the University of Birmingham, UK, who was not involved in either study.

In some previous experiments, ejaculated human sperm have been shown to swim towards areas with high levels of progesterone. The hormone also causes the cells to beat their whip-like tails more powerfully to make it through to the egg, a condition called hyperactivity. “We’ve got good reason to think that the response to progesterone matters, but it’s bloody difficult to pin it down,” says Publicover.

Changing channel

The latest studies, led by independent teams in Germany and the United States who agreed to publish their findings simultaneously, show that progesterone activates a molecular channel called CatSper, which floods sperm cells with calcium.

Mice without the channel are infertile, as are some men with mutations in the genes that make it, says Polina Lishko, a reproductive biologist at the University of California, San Francisco, who led one of the studies2. Sperm that don’t make CatSper cannot become hyperactive.

Lishko and Kirichok’s team developed a way of measuring the electrical currents within sperm that are created by ions like calcium, similar to how neuroscientists record the electrical activity of neurons. They found that adding progesterone to ejaculated human sperm boosts the current, and that treating sperm with drugs that block CatSper reduces it. Putting the cells into high-pH environments, like those found around the egg, also activated CatSper. A combination of high pH and high progesterone had an even stronger effect.

A second team, led by Benjamin Kaupp, a biophysicist at the Center of Advanced European Studies and Research in Bonn, Germany, came to the same conclusion in their own experiments1. They also measured calcium levels within human sperm, and found that the effects of administering progesterone are almost instantaneous. Kaupp says that this quick action leaves little time for traditional molecular-signalling pathways to act, and suggests that CatSper itself detects the sex hormone and causes calcium levels to rise.

Problems with progesterone sensing could explain some cases of infertility, says Kaupp. “It could be that some eggs do not produce enough progesterone, or that some sperm are not as sensitive to progesterone as others.”

Yet there would be little demand for infertility drugs that activate CatSper, says Kaupp, because infertility is already well-addressed by in vitro fertilization. More promising, say researchers, are drugs that stymie conception by hindering the channel’s ability to sense progesterone — or to work at all.

“The consequence for humans is that if you could block CatSper it would be an ideal contraceptive,” says David Clapham, a biochemist at Children’s Hospital Boston in Massachusetts, whose team discovered the channel and are looking for drugs that inhibit it. Sperm are the only cells known to make CatSper, so such a drug is unlikely to have many side effects. It would also, presumably, work regardless of whether it is men or women who take it because it could act on sperm regardless of their location, adds Lishko.

source: nature news